Why is it so hard to go into the User CP, click on edit ignore list and add a username there?

It may not ignore the whole thread someone you don't care for posts in, but it will not display his/her post to you. Does almost the same thing your script as your script, which 90% of people here including myself don't know how to implement, or don't really have the need to implement it.

Some of you guys are way too sensitive. Seriously.